Source $XDG_CONFIG_HOME/cdm/cdmrc as fourth option

README.md

@@ -15,6 +15,7 @@ existing one:
     [RCFILE specified on command line]
     $HOME/.cdmrc
     /etc/cdmrc
+    $XDG_CONFIG_HOME/cdm/cdmrc
 
 To autostart cdm when you log in your account, copy the content of
 /usr/share/doc/cdm/profile.sh to the tail of your shell profile (~/.profile,

src/cdm

@@ -67,6 +67,8 @@ elif [[ -f "$HOME/.cdmrc" ]]; then
     source "$HOME/.cdmrc"
 elif [[ -f /etc/cdmrc ]]; then
     source /etc/cdmrc
+elif [[ -f "$XDG_CONFIG_HOME/cdm/cdmrc" ]]; then
+    source "$XDG_CONFIG_HOME/cdm/cdmrc"
 fi
 
 # Default options.